Always remove jewelry like rings, watches, and necklaces so they don't catch on obstructions.

Don't wear loose clothing or wear your hair long while working on a car. Not only will it get dirty, it could get caught on moving parts.

Work outdoors if you need to have your car running. Exhaust gases can be lethal if you are working inside your closed garage.

Don't smoke while working on your car. There are many flammable substances that could ignite.

Don't open the cap on the radiator when it's hot (right after the car has been running for a while). The hot fluid inside is under tremendous pressure and can shoot out and burn you.

Use a jack stand or drive up ramps to support your car if you need to go underneath it. Factory jacks are only for changing tires.

Most fluids around a car are toxic. Keep kids and pets away while working to avoid accidental poisoning.

Electric cooling fans mounted on the radiator can turn on and off at any time. (There's actually a thermostat switch that controls the fan) Avoid the fan when working or disconnect the fan motor from the power source.